Cylindrical brush for a sweeping machine

ABSTRACT

A sweeping machine for picking up debris from a surface includes a frame and wheels attached to said frame to support the frame of the sweeping machine over the surface being swept. A cylindrical brush is rotatably attached to said frame. The cylindrical brush includes a pattern of rows of sweeping material having N sections that have a first spiral in a first direction and N+1 sections of the brush that have a second spiral in a second direction. Two of the N+1 sections having the second spiral are located on the ends of the brush. The spiral is selected so that it augers or moves debris from a desired or selected side of the sweeping machine toward the center of the brush. The sweeping machine also includes a mechanism for rotating said cylindrical brush.

FIELD OF THE INVENTION

The present invention relates to the field of sweeping machines. Moreparticularly, this invention relates to a brush for a sweeping machinefor picking up various types of debris from a surface being swept.

BACKGROUND OF THE INVENTION

There are many types of sweeping machines for removing various types ofdebris from a surface, such as the ground, a floor or a parking lot.Many of these sweeping machines use a rotating cylindrical brush tocontact the surface being swept. The rotating cylindrical brush is usedto lift various types of debris from the floor or surface and throw itinto a debris hopper located near the rotating cylindrical brush. Themachine moves the rotating cylindrical brush over the surface beingswept. The rotational velocity of the cylindrical brush produces avelocity at the ends of the brush that differs from the velocity of themachine as it moves over the surface being swept. The brush can berotated in either direction. There are many types of sweepers. Two typesof sweepers are forward throw sweeper and indirect throw sweepers.Forward throw sweepers use a brush rotated backward with respect to thetravel of the sweeping. The debris is thrown forward and collected in acontainer which is forward of the brush. Indirect throw or over-the-topsweepers use a brush rotated in either direction with a debris containerlocated for collection of the debris.

Sweeping machines are used in a variety of environments. For example,some sweeping machines remove debris from roads and streets. Others areused to remove debris from parking lots and others are used to removedebris from factory floors. In short, there are many applications forsweeping machines. Sweeping machines also remove different types ofdebris. Certain brush designs can be employed to enhance a sweepingmachine's ability to pick up or remove certain types of debris.

There are several types of brush fill patterns which are customarilyused. One predominant type of brush fill pattern is termed full fill orhigh density. In a full fill type brush the bristles or other sweepingmaterial are closely packed together or in a highly dense configuration.The bristles or other sweeping material of a full fill brush can beplaced in almost any type of pattern to form a full fill type brush. Thefull fill brush presents a substantially solid mass of bristles or othersweeping material. Full fill type brushes are generally effective inremoving relatively thin layers of fine material from surfaces beingswept. Fine materials, also referred to as fines, include very fineparticles, such as sands which are used in foundries for making molds,cement dust, and sand found in parking lots or in streets.

A second predominant type of brush fill pattern has spaces between rowsof bristles or other sweeping material. This second type of brush has anumber of variations. For example, a brush called a double row brush hastwo rows of closely spaced bristles or other sweeping material. This iscalled a double row. There is a larger space between each double row ofbristles or other sweeping material. This second type of brush fillpattern is better for removing bulkier debris or deeper layers of finematerial.

The second predominant type of brush fill pattern is formed by placingthe bristles or other sweeping material in one of several patterns. Onepattern is to place the bristles or other sweeping material in straightlines along the brush tube. The straight lines are substantiallyparallel to the axis of the brush tube. Brushes with straight linepattern of bristles or other sweeping material and spaces between thestraight bristles or other sweeping material cause a brush to bounce orjump excessively because as the brush rotates, the brush alternatesbetween having all the bristles or other sweeping material in one row ofthe brush in contact with the surface being swept and no bristles incontact with the surface being swept. The result of brush bounce ischatter lines of fine debris being left on the surface that has beenswept. Brush bounce may also cause vibration of the sweeping machine.

To prevent the brush from bouncing, the rows of bristles are placed inspiral patterns along the surface of the brush tube. The spiral patternhas a number of spiral tufts placed in a pattern with spaces between thespiral pattern of tufts of sweeping material. When the tufts and spacesare in a spiral pattern, the amount of brush material in contact withthe surface being swept is substantially constant as the brush rotatesso as to minimize the amount of brush bounce. In other words, at anyrotational position of the brush, there is always some brush fillmaterial in contact with the surface being swept to support the brush asit rotates. Spiral pattern brushes also have a problem. Debris or finesmay travel along the length of the brush. The spiral pattern havingspaces between the spirals acts as an auger that may move the debris orfines in one direction along the surface of the brush. This can be adisadvantage since some debris or fines may be augured out at one end ofthe brush.

To prevent fines and debris from traveling along the length of thebrush, many brush designs use a single or double herringbone pattern tobreak up the auguring effect. The herringbone pattern may also be termeda chevron pattern or may be termed as alternating spirals. Theseherringbone patterns prevent the migration of debris and material beingswept from being augured down the length of the brush. The herringbonepattern allows material being swept to only travel to the point wherethe spiral changes directions. As a result, these types of brushes aremore effective at sweeping up certain types of debris and preventing theauguring along the entire length of the brush during rotation.

Herringbone type brushes do auger debris a certain length. Theherringbone patterns can be thought of as using one full chevron or amultiple of one full chevron. One full chevron will have a first spiralin a first direction and a second spiral in a second direction. Brusheswhich do use the herringbone patterns auger debris along the length ofthe spiral until the spiral changes directions. The problem with apattern of brush which has a number of full chevrons or an the samenumber of different direction spirals is that at both ends of thecylindrical brush, the debris or material being swept will be eitheraugured outward or inward from the end of the cylindrical brush. Thedirection of auguring is dependent on the orientation of the chevronswith respect to the rotational direction of the brush. It is desirableto rotate the brush so that the debris and fines auger toward the middleof the brush. However, if the chevrons on the brush are always orientedone way, the bristles or brush material forming the brush can take aset. In other words, like a push broom, the bristles or brush materialcan bend over and become less effective. To prolong the life of acylindrical brush, regular maintenance requires that the brush beswitched or flipped end to end to change the orientation of the chevronsand prevent the bristles or other sweeping material or brush fillmaterial from taking a set in one direction. Flipping the brush end toend changes the direction of the force on the tufts or bristles of thebrush. When flipped or switched, the chevrons of the cylindrical brushwill auger debris toward both ends of the brush which increases thepossibility of trailing. Trailing is where some amount of debris orfines is left at the ends of the brush after the sweeping machine haspassed.

Auguring of fines or other debris is troublesome when you consider thatmany times much of the debris is located on one end of the brush. Forexample, in streets it has been found that the vast majority of thedebris and fines are located on one end of the brush, mainly near thecurb and in the gutter. In this instance, there is a need for acylindrical brush for use on a sweeping machine that will auger thefines or other debris inward toward the center of the brush while it isrotating no matter what orientation of the brush fill pattern of thecylindrical brush. There is also a need for a cylindrical brush thatwill prevent the material being swept from traveling along the entirelength of the brush. There is also a need for a brush that will augerthe debris or fines being swept in toward the center of the brush from aselected or desired side of a sweeping machine even when the brush isflipped end-for-end and the brush fill material is re-orientated. Forexample, it is necessary to have a brush that will auger the materialbeing swept inward despite whether it is in a first orientation orwhether it has been flipped end-to-end to a second orientation formaintenance purposes. There is also a need for a sweeping brush thatwill consistently pick up varying types of debris on a variety ofsurfaces and one that limits axial migration of debris toward the endsof a rotating cylindrical brush. There is also a need for a brush thatminimizes trailing. There is a further need for a sweeping machine thatis smooth and stable during its operation.

SUMMARY OF THE INVENTION

A rotatable cylindrical brush for a sweeping machine includes a tubehaving sweeping material or brush fill material attached to the core orbrush tube. The sweeping material extends radially outward from thesurface of said core or brush tube. The sweeping material forms aplurality rows. A row has a first spiral section in a first directionlocated on one end of the core and a third spiral section in a firstdirection located on the other end of the core. A second spiral sectionspiraling in a second direction is located intermediate the first andthird spiral sections at the ends of the core or brush tube. Asmentioned, there is more than one row. The rows are spaced from oneanother so that the space forms a similar pattern. The brush can also bethought of as having a plurality of sections having a plurality of rows.The brush includes n+1 spiral sections in a first direction, and nspirals in a second direction. The rows on the brush can also be thoughtof as forming a "V" or chevron pattern with an additional spiralattached to the end of a full "V" or chevron. The spiral sections at theend of the brush are oriented so that one selected or desired end of thebrush augers debris in toward the middle of the brush.

Advantageously, as the debris is augured inward from a selected ordesired end, the debris is restricted in its travel along the length ofthe cylindrical body of the brush. The debris is also moved from thedesired or selected end of the brush for effective sweeping withminimized trailing or debris at the desired or selected end of thecylindrical brush. The brush can also be flipped end-to-end therebyre-orientating the brush fill pattern and the bristles with respect tothe surface being swept. After being flipped, the brush will still augerdebris inward from a desired or selected side of the sweeping machine.An additional advantage is that a sweeping machine equipped with thecylindrical brush mentioned above picks up or sweeps all types ofdebris.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the sweeping machine.

FIG. 2 is a front view of a full fill type of cylindrical brush for asweeping machine.

FIG. 3 is a front view of a spiral cylindrical brush for the sweepingmachine.

FIG. 4 is a front view of a cylindrical brush having a herringbonepattern.

FIG. 5 is a front view of a cylindrical brush for the sweeping machinehaving a double herringbone pattern.

FIG. 6 is a top schematic view of a cylindrical brush having a patternwith a herringbone plus an added spiral pattern and attached thesweeping machine.

FIG. 7 is a front view of a cylindrical brush for the sweeping machinehaving a pattern with a herringbone plus an added spiral pattern.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings which form a part hereof,and in which are shown by way of illustration specific embodiments inwhich the invention may be practiced. It is to be understood that otherembodiments may be utilized and structural changes may be made withoutdeparting from the scope of the present invention.

FIG. 1 is a side view of a forward throw type sweeping machine whichuses a preferred embodiment of the present invention. It should be notedthat the brush can be used on any type of sweeping machine and that theone shown in FIG. 1 is for the purpose of illustration. The sweeper 110has a frame 112 and is supported on a surface to be swept 114 by twofree rolling front wheels 116 (only one shown) and one steerable,powered rear wheel 118. Provisions for a driver are indicated generallyby a seat 120 and a steering wheel 122. Other conventional controls arealso provided, but are not shown.

A cylindrical sweeping brush 124, is mounted in a conventional mannerand extends across most of the transverse width of the sweeping machine.It is supported between two brush arms 126 (only one shown) which areattached in pivotal manner to the sides of the frame 112 at twotransversely aligned points 128 (only one shown). A cross shaft 130joins the two brush arms 126 together so that both ends of brush 124 aremaintained in alignment. A lift arm 132 is welded or otherwise attachedto one brush arm, and is pivotally connected at its upper end to a cableassembly 133. This connects to a hydraulic cylinder 134 which is used toraise the brush 124 off the surface 114 for transport, or lowered to itsworking position as shown in FIG. 1. In working position, cable assembly133 may be slack. The engagement of brush 124 with surface 14 may becontrolled by an adjustable down stop (not shown). This may be made inany one of several conventional ways. Commonly such a stop is a heavyscrew bearing against a lug welded to cross shaft 130. A knob on theopposite end of the screw will be accessible to the driver. By turningthe knob, the driver or operator can set the brush height for a desiredfloor contact, or pattern, and can re-set it when needed as the brushwears. Brush 124 is rotated by a hydraulic motor. This motor is suppliedby hoses 136. The opposite brush arm 126 (not shown) carries an idlerbearing assembly which rotatably supports the opposite end of brush 124.The sweeper 110 also includes a planar side sweep brush 610 (shown inFIG. 6) which is used to sweep debris away from a desired side of thesweeping machine. The side sweep brush 610 places debris or fines infront of the cylindrical brush 124 so that it can be swept and placedinto the hopper 168 of the sweeping machine. The side sweep brush 610can also be positioned to increase the effective sweep width of thesweeping machine beyond the path of the cylindrical sweeping brush 124.

FIGS. 2-5 are front views of conventional brushes that have been used onsweeping machines 110. The brush 200 shown in FIG. 2 has been removedfrom the sweeping machine 110 so that the pattern can be easily viewed.The brush 200 is a cylindrical sweeping brush and further comprises acore or brush tube 210. The core 210 is a member to which sweepingmaterial 220, such as tufts of bristles, can be attached. The core orbrush tube 210 is also capable of being rotated. The core of any of thebrushes described, could be a tube, a hollow cylinder, a solid cylinder,entwined metal members or the like. It should be noted here that brush200 shown in FIG. 2 is populated by bristles or sweeping material withfull-length bristles. Sweeping fill material 220, such as as bristles,can be made of polypropylene, nylon, polyester, or other synthetics. Thebrush fill material 220 can also be made of brush wire, or fillmaterials of a plant or animal origin. The cross sectional size andshape and the length of the bristles can also be varied to tailor thecylindrical brush 200 for a particular purpose.

In a full fill type brush 200 the bristles or other sweeping fillmaterial 220 are closely packed together or in a highly denseconfiguration. The full fill type brush 200 has no discernable pattern.The bristles or other sweeping material 220 of a full fill brush 200 areso closely packed that they can be placed in almost any type of patternto form a full fill type brush. The full fill brush presents a solidmass of bristles or other sweeping material. Full fill type brushes 200are effective in removing relatively thin layers of fine material fromsurfaces being swept.

Now turning to FIG. 3, we see another conventional brush which is aspiral type cylindrical brush 300. The bristles or sweeping fillmaterial 220 is placed in spiral pattern along the surface of the coreor brush tube 210. The spiral pattern has a number of spiral rows 310 oftufts of brush fill material 220 with alternating spiral spaces 320between the spiral rows of sweeping material. When the bristles andspaces are in a spiral pattern, the amount of bristle or brush materialin contact with the surface being swept is substantially constant as thebrush rotates so as to minimize the amount of brush bounce. In otherwords, at any rotational position of the brush, there is always somebrush fill material in contact with the surface being swept to supportthe brush as it rotates. When the sweeping fill material 220 is in aspiral pattern, debris or fines may travel along the length of the brush300. The spiral rows 310 of the brush material 220 and the spiral spaces320 in the pattern act like an auger that may move the debris or finesin one direction along the surface of the brush 300.

FIGS. 4 and 5 show brushes that have a herringbone pattern and a doubleherringbone pattern, respectively. Brush 400 has brush fill material 220attached to a brush tube or core 210 to form rows 410 in a herringbonepattern. The pattern also features spaces 420 between rows which arealso in a herringbone pattern. Each row 410 can be made of a one or morerows of sweeping fill material 220. In other words, two rows could bepacked closely together to form a thicker herringbone pattern row 410.The herringbone pattern can also be thought of as chevron pattern or a"V"-shape pattern. The pattern that the row 410 makes is characterizedin that it has a first spiral in one direction attached to a secondspiral in a second direction. The first direction may be acounterclockwise spiral like a right hand thread. The second directionmay be a clockwise spiral like a left hand thread. The herringbonepattern is characterized in that there are an equal number of spiralsections of the brush in a first direction and an equal number ofspirals on the brush in a second direction.

As shown in FIG. 4, the brush 400 has one section of the brush 400 orone end, which has a spiral in a first direction and the other end ofthe brush has a second spiral in a second direction. The herringbonepattern is advantageous in that when the brush 400 is rotated in aparticular direction, the debris or fines will be augured in toward thecenter of the brush 400. Herringbone patterns are used to prevent thetransport of debris or fines or material beings swept along the entirelength of the brush 400. Fines or materials being swept can betransferred or moved across the entire length of the spiral brush. Theherringbone pattern acts to break up this transfer movement of debris orfines. The problem with the herringbone brush is that a regularmaintenance item for most brushes is that they must be flippedend-to-end on a sweeper 110 periodically to re-orientate the brush fillmaterial. The end result is that the force on the brush fill material isin the opposite direction after the brush has been flipped. Thisprevents the brush fill material from taking a set in one direction.With a herringbone brush 400 when the brush is flipped end-to-end, thedirection which the debris or fines is augured is changed so that thedebris and fines are augured out toward the ends of the brush 400.

FIG. 5 shows a double herringbone brush 500. In a double herringbonebrush 500, the row 510 and brush material 220 is in a pattern with twoherringbones connected end-to-end. The herringbones can also be thoughtof as "V's" or chevrons. Again the brush 500 can be broken into foursections. In the first and second sections the spiral is in a firstdirection. In the third and fourth sections of the brush 500, the spiralis in a second direction. Just like the brush 400, the brush 500 has thesame number of spirals in the first direction as in the seconddirection. The problems associated with the single herringbone brush 400are the same as those associated with the double herringbone brush 500.One of the problems is that when the brush is rotated in oneorientation, debris and fines are augured in toward the center of thebrush, but when the brush is flipped end-to-end to re-orientate thebrush fill material, the debris and fines are augured in the oppositedirection toward the ends of the brush 500.

FIG. 6 shows a top view of a sweeping machine 110 that includes theinventive brush 124 and also has a side sweep brush 610. The outline ofthe sweeping machine 110 is shown in phantom. The side sweep brush 610removes debris from a desired or selected side of the sweeping machine110 and places it in front of the brush so that it can be effectivelyswept up by the main brush 124. The side sweep brush also extends thesweeping path of the sweeping machine 110. The brush 124 includes abrush tube or core 210 which has bristles or other sweeping material 220attached to the brush tube in a pattern which forms rows 630 of sweepingmaterials and spaces 620 between the rows of sweeping material. The rows630 have bristles or sweeping material 220 formed in a zig zag pattern.The zig zag pattern has N spirals in a first direction and N+1 spiralsin a second direction. The spirals in the second direction are locatedon the ends of the core or the brush tube 210 in each row 630. Thepattern of the brush 600 can also be thought of as a double herringbonepattern with an additional spiral. The pattern can also be thought of ashaving a series of full chevrons or "V's" with an additional half of achevron or half of a "V". The pattern is characterized in that the brushmay be divided into sections in which there are N+1sections having aspiral and a first direction and N sections having a spiral in a seconddirection. The cylindrical sweeping brush 600 has two ends. One end issituated near a preferred, desired or selected side of a sweepingmachine 110. Although not always true, in most instances the side sweepbrush 610 is positioned on the preferred side of the sweeping machine.

The zig zag rows of spiral 630 are oriented so that when the brushrotates the lead tufts at the desired side of the sweeping machine 110will tend to auger debris inward or toward the center of the brush. Theadvantage of this brush is that when it is flipped end-to-end as part ofmaintenance of the machine, the auguring effect at the desired orpreferred end of the brush will continue to move debris inward. In otherwords, when the brush 600 is flipped, the auguring effect continues tomove debris in a direction from a desired side of the sweeping machine110 toward the center of the brush. This is advantageous in that in someapplications much of the debris may be at the desired side of a sweepingmachine 110. For example, in a street sweeper, much of the debris is atthe curb side of the sweeping machine 110 during normal sweepingconditions. As a result, there is less possibility for trailing orleaving a trail of fines such as sand, at the desired side of thesweeping machine.

FIG. 7 shows a brush 700 which includes rows of 710 sweeping fillmaterial 220 which are formed in a zig zag pattern. Each row 710includes a spiral section. The first and third spiral sections are inthe same or in a first direction and are at the ends of the brush. Thesecond spiral section is attached to the first and third spiral sectionand is in a different direction or second direction. The brush,therefore has N+1 sections in a first spiral direction and N spirals ina second direction. In the case of the brush shown in FIG. 7, N=1. Thebrush 700 can also be thought of as a single herringbone having an addedspiral; or thought of as a single chevron plus half a chevron; orthought of as a single "V" plus half of another "V". It should be notedthat the pattern on the brush is orientated so that when it rotates thebrush augers inward from a desired side of the sweeping machine. Itshould be noted that N can be any number. By increasing the number N, itmerely increases the number of chevrons or v's formed in the row 710 ofthe brush 700. Each row 710 is spaced apart from an adjacent row. Thespaces carry the reference numeral 720.

Advantageously, since the debris augured inward from the desired side ofthe sweeping machine 110, the debris is restricted in its travel alongthe length of the cylindrical body of the brush. The brush also movesthe debris from the desired side of the sweeping machine for effectivesweeping with minimized trailing or debris escaping at the one end ofthe cylindrical brush. The brush can also be flipped end-to-end and theend of the brush located at the desired or selected side of the sweepingmachine will still auger debris in toward the center of the brush. Anadditional advantage is that a sweeping machine 110 equipped with thecylindrical brush mentioned above picks up or sweeps all types ofdebris.

As mentioned above and as seen in the several preferred embodimentsdescribed herein, there are many different types of brush fillmaterials. In addition, there are many different brush tube types. Brushtubes can be made of wood, paper, plastics, or other materials. Inaddition, brush tubes can be made of composites of several materials.The tufts or grouping of individual bristles can be attached to thetubes in a number of ways as well. For example, the tufts may be stapledto the brush tube or may be constructed of strip brushes. It should benoted that the invention described herein can be made using any type ofbrush fill material, any type of tube and using any way of attaching thebristles to the tube to form a brush in which the sweeping materialforms a plurality of first regions of sweeping material and a pluralityof second regions devoid of sweeping material.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reviewing the abovedescription. The scope of the invention should, therefore, be determinedwith reference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. A sweeping machine for picking up debris from asurface, said sweeping machine comprising:a frame having a first brushattachment element and having a second brush attachment element; wheelsattached to said frame, said wheels for supporting said frame over saidsurface; a cylindrical brush rotatably attached to said frame at thefirst brush attachment element and at the second brush attachmentelement, said cylindrical brush further comprising:a cylindrical bodyhaving first and second ends; and sweeping material attached to saidcylindrical body to form a brush having a plurality of spaced apartrows, said rows including a herringbone pattern having a spiral in afirst direction attached to a spiral in a second direction, one of saidfirst direction or second direction spirals positioned on the first endof the cylindrical body, said row further comprising an additionalspiral attached to the second end of the cylindrical body, saidadditional spiral rotating in substantially the same direction as thespiral positioned on the first end of the cylindrical body, thecylindrical body rotating so that the sweeping material moves debristoward the middle of the cylindrical body from one of the first andsecond ends of the cylindrical body in a first rotational orientation,and moves debris toward the middle of the cylindrical body from one ofthe first and second ends of the cylindrical body in a second rotationalorientation, said first rotational orientation differing from the secondrotational orientation in that the brush is flipped end to end from thefirst rotational orientation to the second rotational orientation; and amechanism for rotating said cylindrical brush.
 2. The sweeping machinefor picking up debris from a surface of claim 1 wherein the first end ofthe cylindrical brush can be rotatably attached to one of the firstbrush attachment element and the second brush attachment element andwherein the second end of the cylindrical brush can be rotatablyattached to the other of the first brush attachment element and thesecond brush attachment element on the frame.
 3. The sweeping machinefor picking up debris from a surface of claim 2 wherein debris isaugured away from a side of the frame of the sweeping machine before andafter the brush is flipped end-to-end with respect to said frame.
 4. Thesweeping machine for picking up debris from a surface of claim 1 furthercomprising an arm attached to said cylindrical brush for controlling theamount of force applied between the cylindrical brush and the surface.5. A method for sweeping with a brush, said brush including acylindrical body having first and second ends, and sweeping materialattached to said cylindrical body to form a brush having a plurality ofspaced apart rows, said rows including a herringbone pattern having aspiral in a first direction attached to a spiral in a second direction,one of said first direction or second direction spirals positioned onthe first end of the cylindrical body, said row further comprising anadditional spiral attached to the second end of the cylindrical body,said additional spiral rotating in substantially the same direction asthe spiral positioned on the first end of the cylindrical body, saidmethod comprising the steps of:rotating the cylindrical body of thebrush in a selected direction so that the sweeping material moves debristoward the middle of the cylindrical body from one of the first andsecond ends of the cylindrical body; flipping the cylindrical bodyend-to-end; and rotating the cylindrical body of the brush in theselected direction, said sweeping material moving debris toward themiddle of the cylindrical body from one of the first and second ends ofthe cylindrical body.